1. Field of the Invention
The disclosed embodiments of the present invention relate to iteratively decoding soft information, and more particularly, to an iterative detection and decoding device selecting soft information according to predetermined constrained rules, and a related iterative detection and decoding method.
2. Description of the Prior Art
Iterative detection and decoding is a technique that improves the overall performance of a communication system, wherein soft information is exchanged between a signal detector and an error-correction decoder (e.g. a Low-Density Parity-Check decoder) to iteratively derive the desired message. The signal detector can benefit from both the received signal and additional information of the coded bits. Traditionally, all the soft information generated by the decoder is passed to the signal detector regardless of the reliability of the soft information. Although such a scheme is acceptable for most applications, possible decoding failure may still occur, leading to degradation of error-correction performance.
Therefore, how to prevent unreliable soft information from being passed to an error-correction decoder is an issue to be solved in this field.